renderThenElse

fn renderThenElse(
    r: *Render,
    last_prefix_token: Ast.TokenIndex,
    then_expr: Ast.Node.Index,
    else_token: ?Ast.TokenIndex,
    maybe_error_token: ?Ast.TokenIndex,
    opt_else_expr: Ast.Node.OptionalIndex,
    space: Space,
) Error!void {
    const tree = r.tree;
    const ais = r.ais;
    const then_expr_is_block = nodeIsBlock(tree.nodeTag(then_expr));
    const then_expr_first_token = tree.firstToken(then_expr);
    const indent_then_expr = !then_expr_is_block and
        (!tree.tokensOnSameLine(last_prefix_token, then_expr_first_token) or
            tree.tokenTag(then_expr_first_token) == .multiline_string_literal_line);

    if (indent_then_expr) try ais.pushIndent(.normal);

    if (then_expr_is_block and ais.isLineOverIndented()) {
        ais.disableIndentCommitting();
        try renderToken(r, last_prefix_token, .newline);
        ais.enableIndentCommitting();
    } else if (indent_then_expr) {
        try renderToken(r, last_prefix_token, .newline);
    } else {
        try renderToken(r, last_prefix_token, .space);
    }

    if (opt_else_expr.unwrap()) |else_expr| {
        if (indent_then_expr) {
            try renderExpression(r, then_expr, .newline);
        } else {
            try renderExpression(r, then_expr, .space);
        }

        if (indent_then_expr) ais.popIndent();

        var last_else_token = else_token.?;

        if (maybe_error_token) |error_token| {
            try renderToken(r, last_else_token, .space); // else
            try renderToken(r, error_token - 1, .none); // |
            try renderIdentifier(r, error_token, .none, .preserve_when_shadowing); // identifier
            last_else_token = error_token + 1; // |
        }

        const indent_else_expr = indent_then_expr and
            !nodeIsBlock(tree.nodeTag(else_expr)) and
            !nodeIsIfForWhileSwitch(tree.nodeTag(else_expr)) or
            tree.tokenTag(tree.firstToken(else_expr)) ==
                .multiline_string_literal_line;
        if (indent_else_expr) {
            try ais.pushIndent(.normal);
            try renderToken(r, last_else_token, .newline);
            try renderExpression(r, else_expr, space);
            ais.popIndent();
        } else {
            try renderToken(r, last_else_token, .space);
            try renderExpression(r, else_expr, space);
        }
    } else {
        try renderExpression(r, then_expr, space);
        if (indent_then_expr) ais.popIndent();
    }
}